1. Field of the Invention
The present invention relates to a process for producing ammonium p-styrenesulfonate from an alkali metal p-styrenesulfonate.
2. Description of the Prior Art
Heretofore, it has been known that ammonium salts of organic sulfonic acids can be produced easily by neutralizing the corresponding sulfonic acids with ammonia. However, in the production of ammonium p-styrenesulfonate, the precursor p-styrenesulfonic acid is not easily produced by such conventional techniques as sulfonation of styrene or the like. Accordingly, it is difficult to utilize the usual methods. As shown in the disclosure of Japanese Patent Publication No. 14220/1960, it has been known that alkali metal p-styrenesulfonates can be produced by reacting an alkali hydroxide with .beta.-haloethylbenzenesulfonic acid.
The inventors have previously attempted to produce ammonium p-styrenesulfonate from alkali metal p-styrenesulfonate, and have found that ammonium p-styrenesulfonate can be produced by reacting an inorganic ammonium salt with an alkali metal p-styrenesulfonate in an alcohol solvent or in a mixture of an organic solvent with water. However, it is very difficult to prevent the contamination of the product by a small amount of alkali metal component. Consequently, a need continues to exist for an effective process for preparation of ammonium p-styrenesulfonate in a non-contaminated form.